MELISSA HANSEN: Yeah, somebody who...someone who had a little glimmer of
mischief in his eyes, you know, a spirit behind it.

BOB SULLIVAN: Well, and sex appeal, because sex sells.

MELISSA HANSEN: Sex appeal is so important.

NARRATOR: But what if the script says your leading man is a
dog? Is this the right look? Or is it this? Or this? Fact is, dogs come in more
shapes and sizes than any other mammal on the planet, and there's no shortage
of opinions about what's sexy in a dog.

But this commercial is designed to sell fabric deodorizer, and it calls for
a sexy "everydog" kind of dog, which is why Dino got the job.

MELISSA HANSEN: Dino has this incredible presence—that sort of
everyday quality, that sort of down-to-earthness. He came across in the first
casting tape. It was great. It didn't hurt that Dino's more than just a pretty
face. He's the kind of performer who's willing to do his own stunts.

BOB SULLIVAN: We were thinking we were going to have to do computer
animation, and we were going to have to do all kinds of techniques. And within
a week, all of a sudden the director calls us and he goes, "I can't believe it,
the dog can spray the bottle."

TRAINER: Foot! Foot! One more time. Foot! Good.

DIRECTOR: That's a cut, that's a cut.

TRAINER: Foot! No. Stay! Foot!

NARRATOR: Not bad for a dog who was abandoned and brought to
the Las Vegas pound. That's where his trainers found him five years ago.

TRAINER: Down! Good boy.

Now he's a star.

NARRATOR: Tonight, NOVA tells the true story of dogs. How did
a fierce wolf become a playful puppy? Why do they come in so many shapes and
sizes? And what does the future hold for our oldest and closest animal
companion? Dogs and More Dogs, right now on NOVA.

Major funding for NOVA is provided by the Park Foundation, dedicated to
education and quality television.

We see 400 employees in three years. At Microsoft your potential inspires us
to create software that helps you reach it. Your potential, our passion.

Science: it's given us the framework to help make wireless communications
clear. Sprint is proud to support NOVA.

And by the Corporation for Public Broadcasting, and by contributions to your
PBS station from viewers like you. Thank you.

NARRATOR: In many ways, the Levines are a typical American
family, always on the run. Perhaps life would be better, some of them believe,
if only they had...

LILY MIRELS LEVINE: ...dog, we need a dog.

AARON LEVINE: A dog would be great!

ELI LEVINE: I want a really big dog!

MIKE LEVINE (Geneticist, University of California at Berkeley): A
dog, in our family, it's crazy.

LILY MIRELS LEVINE: I think it's a really good thing to grow up knowing
what it's like to have a pet.

MIKE LEVINE: I just don't particularly like dogs. They've always struck
me as being rather big, smelly...they shed all over the place.

LILY MIRELS LEVINE: He never had a dog when he was a kid, and truth be
told, I think he's a little afraid of them.

MIKE LEVINE: Personally, I'm more of a bug guy. I like flies,
butterflies, things like that.

NARRATOR: Little creatures can help a geneticist like Mike
Levine explore life's mysteries, but he's never been able to understand the
passion that people have for their big, messy, demanding canine companions.

JOE VERGNETTI: They're kind of like your children. You're proud of
them, and you try to make them perfect and trim them and have them look
beautiful.

MAN WITH ROTTWEILER: He is so smart, he is so obedient.

MAN WITH BULLDOG: He's a beautiful, beautiful dog.

WOMAN WITH BASSET: The best thing in the world is to come home and have
somebody happy that you're there.

MAN WITH ROTTWEILER: I'd marry this dog if it was a woman.

OFF CAMERA VOICE: What is it that a dog does for you?

MAN WITH LITTLE DOG: Well...a lot more than my wife.

MIKE LEVINE: I've held out now for, I would say...10 years there's been
talk of dogs. And finally the time has come where I have to relent and allow a
dog in.

NARRATOR: Which is why Mike recently found himself checking
out potential new family members. And while he doesn't fall in love, he is
unexpectedly intrigued.

MIKE LEVINE: There is one cool thing about dogs, I have to reluctantly
admit, and it is all the varieties: different shapes, different sizes,
different colors. It's an extreme example of evolutionary diversification.

NARRATOR: The Levines come home with a little mixed breed dog
named Taxi. Fulfilling every one of Mike's expectations, Taxi's first day
includes throwing up in the living room, peeing in the kitchen, and shedding
hair everywhere. All of which, the boys and Lily get over quickly. It's not so
easy for Mike. He's trying hard, but a month into this grand experiment, Taxi
remains for him less a beloved companion than an example of a fascinating
evolutionary mystery.

MIKE LEVINE: All dogs arose from a fairly homogeneous population of
wolves, something on the order of 10,000 years ago. And that is just a
fascinating scientific problem. How did this one population of animals that all
look more or less alike, give rise to this incredible diversity of dogs in a
relatively short period of time?

NARRATOR: Wolves are one of nature's elite predators. They
hunt with a rare mix of endurance, speed, ferocity and teamwork. Yet these
skilled killers were the first animal to be domesticated. The mystery is: how?
Some say humans made it happen. If so, it's a good bet it wasn't by taming
adult wolves. But a baby wolf, that's another matter. They're pretty
irresistible.

JAMES SERPELL (University of Pennsylvania): We have abundant
evidence from anthropological accounts, ethnographic accounts, of
hunter-gatherers in different parts of the world, capturing and taming young
wild animals and then bringing them home and keeping them as pets.

NARRATOR: Perhaps our ancient ancestors did the same: finding
a wolf pup, falling in love with it, and bringing it home to raise as a pet,
essentially adopting it. And perhaps they keep at it, even though the majority
of pups grow into unpredictable and dangerous adults or simply run away.

JAMES SERPELL: We have to picture maybe thousands of these pet wolves
going through this process and sooner or later when you do this with thousands,
you're going to get some which grow up to be more amenable to living in that
context and less of a threat.

NARRATOR: If so, early humans might have ended up with a wolf
like this. Her name's Maya, and she lives at Wolf Park, a research facility and
tourist attraction in Indiana. Here, staff biologists have turned raising tame
wolves into a science.

WOLF PARK STAFFER: I actually thought about going in and turning around
and trying to come out, but I'm too claustrophobic to be in there that long.

NARRATOR: Their process begins with a midday raid on a den
filled with 10-day-old pups. They've found that the first step in raising tame
wolves is to take them from their mothers at a very early age. For the next
four months, these puppies are with people 24 hours a day, 7 days a week. It's
tricky: do the wrong thing and you can wind up with a grown wolf that's
unpredictable and dangerous.

PATRICIA GOODMAN (Wolf Park): We spend about 2,000 human hours in
a summer—that's not all one human—socializing these puppies to us.
It's an extremely labor intensive process and we're always monitoring each
other's behavior, because it's extremely easy to reinforce the wrong kind of
behavior before you've even realized you've done it.

NARRATOR: All this care produces wolves that aren't threatened
by human smells and sounds. Even so, everyone at Wolf Park moves carefully when
they're with the wolves. Sudden and unexpected gestures can provoke a serious
bite. These animals are only superficially tame; they certainly aren't dogs.

But they could be a first step on the journey to dog. The next step would
be to allow only the tamest wolves in the pack to breed. If you kept that up
generation after generation, in theory, you would create an animal
fundamentally different from these wolves, one with tameness in its genes.

According to some biologists that's essentially how the dog was first
created 15,000 or more years ago. Others think the idea you can get a dog by
adopting a wolf is nonsense.

RAY COPPINGER (Hampshire College): The idea that Stone Age people
could tame and then train and then domesticate a dog is just ludicrous, as far
as I'm concerned. When I think of how much time it takes to train a dog, and
think that those people back there, who had their own problems, and they've got
to spend weeks, months, training wolves, and the wolves are going to put up
with this kind of thing, and they're going to do it generation after
generation, and I'm going to breed my wolf with your wolf? I mean, wolves have
very strict rules about who they breed with, and when they breed, and so on. I
mean, I don't see Stone Age people sitting out there with chain link fences and
all the things that are required for me to breed dogs. They just don't have the
stuff to do it with.

NARRATOR: For Ray Coppinger and other dog experts who reject
the adoption hypothesis, the challenge has been to find an alternative. How
else might the journey from wolf to sled dog—and all the other diverse
forms dogs take—have begun?

It was only when he started thinking about what was in it for the wolves
that Coppinger came up with an answer. Now he's convinced wolves chose
domestication, and they did so because of the easy pickings in a Stone Age
equivalent of this Tijuana dump.

In a dump, an animal that's a little tamer, a little less likely to get
scared off by people, has a better chance of finding food and surviving. It's
true today and, Coppinger argues, it would have been just as true a long time
ago.

RAY COPPINGER: Imagine 14,000 years ago when people first get the idea
of living in a village. They settle down, they build permanent houses, and
around that permanent...those permanent houses, all the waste products of their
economies build up. You've got waste food; you've got waste materials of all
kinds. Now there's a whole set of animals that move in on that. We know them
now: we've got house mice, we've got cockroaches, we've got pigeons, we've got
all kinds of animals that are living off the human waste. One of them is the
wolf. The wolf moves into that kind of a, of a setting, that new niche, that
new foraging area, and it's great. You don't have to chase anything, you don't
have to kill anything. You just wait; people dump it in front of you.

NARRATOR: Not every animal can take advantage of this
resource. Most wild animals run away when humans approach. The few that don't,
have a real advantage. They're going to get most of the food, and that means
their offspring are more likely to survive. Each new generation becomes
increasingly tame.

RAY COPPINGER: The ones that run away the first time anybody shows up,
those are the ones that are going to be selected against, they're going to go
out, have to make an honest living out in the wild. They're not going to be
able to get enough out of that dump. So here's natural selection in action. Any
one wolf that's a little tamer than the other, who can stay there longer, get
more food, he's the one that's going to win that evolutionary battle.

NARRATOR: That's how natural selection works. It's a classic,
if somewhat unexpected, example of survival of the fittest. It's also,
according to Coppinger, the best way to explain many of the physical
differences between dogs and wolves.

RAY COPPINGER: You look at a wolf's mouth, and he's big and he's
got these robust teeth, and you can see him out there killing things. The dog
has little teeth. The wolf has a big brain; the dog's got a little tiny
brain. Well, who in the world has little tiny brains? Animals that don't need
brains. And the dog, you know, a scavenger, doesn't need much of a brain. I
mean it doesn't take a lot of cunning to figure out where a rotten tomato is.
You basically have to be there when somebody throws the tomato away. So you're
kind of a sit and wait animal.

NARRATOR: Was it the lure of our leftovers that ushered in the
era of animal domestication, or was it a matter of puppy love? Either way,
what's critical is that tamer than average individuals somehow gain an
advantage and become more likely to breed.

Of course, that leaves unanswered another problem. Many dogs have floppy
ears, tails that turn up and curl, patchy coats of many colors. These aren't
things you see on wolves, which makes sense because none of them would help a
wolf survive in the wild. It's been suggested that humans consciously bred for
these traits. Ray Coppinger thinks that's more nonsense.

RAY COPPINGER: What do you do? Do you start selecting for a tail? You
know—each generation of tail is going up inch by inch until it gets to
the top. And while the tail is going up the ears are coming down centimeter by
centimeter until they're floppy ears, you know, and so on. From a genetic point
of view, I've got to have a mechanism, I've got to have something there, and
believe it or not, for forever it's been a mystery.

NARRATOR: Traits like coat color, or the way a dog carries its
ears or tail, are determined by its genes. Genes are pieces of DNA, and they
often come in subtly different versions. Every dog gets one copy of every gene
from mom and one from dad. These genes can be mixed and matched in countless
ways, but if the parents don't have it, the pup can't get it.

And that's what makes curly tails and patchy coats in dogs so mysterious.
Wolves don't have them. It took a remarkable experiment in a most unlikely
place, to solve this mystery. The place was the middle of nowhere, Siberia. And
the experimenter was an out-of-favor Russian geneticist named Dmitri Belyaev.

Local fox farmers had asked Belyaev for help in breeding a less vicious
animal. Belyaev began with the tamest foxes he could find. From their
offspring, and for many generations thereafter, he chose only the tamest for
breeding. He'd expected that each new generation would be a little less
vicious, a little more tame. But by the tenth generation, he was seeing things
he'd never expected.

RAY COPPINGER: All of a sudden his fox ears started down, his fox tails
started up, they started to bark, which is not characteristic of foxes. They
started to have different coats, all these little features that you can't
imagine being in the wild type. I mean it's not a matter of selecting for,
because they're not there to be selected for—that variation isn't
there.

NARRATOR: What does tameness have to do with ears, and barking
and coat color? Belyaev and his colleagues immediately went looking for an
explanation. They checked the foxes' adrenaline levels—that's the hormone
that controls the "fight or flight" response—and they found they were far
lower than normal.

RAY COPPINGER: That would explain the tameness, they're just not
afraid because they're not producing as much adrenaline. But where does the
multi-colored coat come from? And somebody says right off the bat, "Hey,
adrenaline's on a biochemical pathway that also goes to melanin, also has
something to do with the animal's coat color." So there's a correlation between
coat color now and the adrenal gland.

NARRATOR: Suddenly, it all started to make sense. As Belyaev
bred his foxes for tameness, over the generations their bodies began producing
different levels of a whole range of hormones. These hormones, in turn, set off
a cascade of changes that somehow triggered a surprising degree of genetic
variation.

JAMES SERPELL: Just the simple act of selecting for tameness
destabilized the genetic make up of these animals in such a way that all sorts
of stuff that you would never normally see in a wild population suddenly
appeared.

NARRATOR: Most dog biologists now believe something very
similar to what happened to these foxes also happened to a population of wolves
more than 10,000 years ago. And the rest, as they say, is history: the world's
first domestic animal.

And from the beginning, dogs have been a remarkably good fit in human
society, thanks in large part to the social skills they inherited from
wolves.

JAMES SERPELL: The key thing, I think, was that dogs are pre-adapted to
living in fairly complicated social groups. Wolf society typically has
quite well-established dominance hierarchies within it. Individuals learn to
slot themselves into that hierarchy and function within that context.

NARRATOR: Low-ranking wolves are adept at sucking up to their
more powerful pack mates. Dogs use many of those same skills with
people.

JAMES SERPELL: So we're getting these signals from our dogs that we are
important, we're loved, we're the greatest thing around. And you know, to me,
it's obvious why we like dogs—because they're so good at showing that
they like us.

NARRATOR: This intimate bond between humans and dogs goes back
a long way—according to one controversial theory, a very long way.

Jennifer Leonard is part of a team at UCLA that studies ancient DNA. She's
come to London's Natural History Museum to collect some really old dog bones
which she hopes will help prove the team's radical new theory.

CURATOR (Natural History Museum): These are some domestic dog remains.
They date to the pre-pottery Neolithic period.

NARRATOR: Even a tiny slice of six thousand-year old dog tooth
contains DNA, and DNA is a window into the ancient origins of the dog.

Back in Los Angeles, Leonard sequences the different
chemicals of the dog's DNA.

These As, Ts, Cs, and Gs come from a small segment of DNA where
mutations—spontaneous changes in the genetic code—harmlessly
accumulate over generations.

NARRATOR: To geneticists, these changes are the ticking of a
crude kind of clock. Leonard's tests and earlier experiments show that
clock has been ticking for dogs for a long, long time.

ROBERT WAYNE (University of California, Los Angeles): I was
amazed. And, principally, I was amazed because of the depth of divergence in
different dogs. It was nothing like you'd expect among a group of animals that
had diverged very recently—12- or 14,000 years. The sequences were
dramatically different.

NARRATOR: This theory suggests that dogs started accumulating
these mutations 100,000 years ago, back when Neanderthals and Homo sapiens were
still duking it out for survival.

This has inspired some pretty far-fetched speculation, like the idea it was
dogs that tipped the evolutionary balance in favor of us and the notion that
dogs gave us a reason to invent language.

In truth, if there were dogs 100,000 years ago, they were probably far more
wolf than dog. But by 10,000 years ago, just about everywhere there were people
there were dogs that looked and acted like dogs. Back then, dogs came in a
pretty standard size and shape. There's no evidence of dogs like this or this.
Or even this.

But by 5,000 years ago, it's clear dogs are no longer "one size fits all."
This shape has survived in dogs like the Saluki, and Salukis are the
Porsches of the dog world. In a three-mile race they can outrun any mammal on
the planet.

ELAINE JOHNSTON (Saluki Breeder): I think the Saluki is an
amazing creature. There's such grace and such power, and such flowing movement
and lines. There's just nothing like it. I mean it just makes my heart sing.

NARRATOR: Today, Salukis are an unusual breed, just as they
were thousands of years ago in Egypt when these creatures were the play toys of
Pharaoh's court.

ELAINE JOHNSTON: I must say that I've never thought of myself as a
little mid-Eastern princess watching her Saluki course across the sands, but
Saluki in full stride—it's the next best thing.

NARRATOR: The Saluki is an engineering marvel. Its long legs
mean it can cover almost 10 feet in a single stride. Its tiny waist allows it
to tuck those legs way up when running—twice in every stride all four
feet are off the ground.

Its heart and lungs are oversized to maximize oxygen intake. Its chest is
narrow to help control heat build-up. Even its long nose helps by cooling the
blood. From a design perspective, Salukis are remarkable. But that doesn't stop
Saluki lovers from trying to breed in a little extra.

ELAINE JOHNSTON: I think that his neck is a little bit too short. He's
got great strength in the neck, but I'd like to have it just a smidgenlonger. I also would like to have a little more muscle definition in the
rear.

NARRATOR: Human intervention in animal breeding is so common
today, it's widely assumed we've been doing it forever. But 6,000 years
ago, no one knew about oxygen uptake and cooling the blood, which is why most
biologists scoff at the idea that this sophisticated running machine was
intentionally bred.

So how did Salukis evolve? Although we may not have bred them, people are a
big part of the story. Dogs have always done things we find useful, and we've
always rewarded the ones that are the best.

Eight thousand years ago, large stretches of the Middle East were open
grassland where small game was abundant and regularly preyed on by hungry
humans. But more often than not, the rabbits were fast enough to send the
humans home empty-handed. Then, one day, a bunch of dogs tagged along on a
hunt. Being dogs, they joined the chase. One of them was faster than the rest,
and caught a rabbit. His master rewarded him with food. A better-fed dog has a
better chance of surviving, attracting a mate, and passing on its genes.

Repeat this process for enough generations and you end up with a sleek,
highly sophisticated racing machine—no assembly required.

RAY COPPINGER: Nobody had to know about a long nose or long legs. All
they had to do was take the dog out there in the desert and have it chase
rabbits. Over the generations of just picking the best dog, the one that can
see the rabbits best, the one that can catch the rabbits, what they do is, they
get longer legs. They didn't breed for longer legs, they just favored those
dogs that had them.

NARRATOR: It's the glory of evolution run fast-forward. Humans
set the conditions for success, reward those animals in each generation that do
the job best, and nature does the rest. That same basic process produced big,
aggressive guardian and war dogs, and small, quick vermin hunters like the
early ancestors of these ratters.

Through our long history together, whenever we've moved to a new
environment or given dogs a new job, we've ended up with very different looking
animals. Yet, remarkably, as different as two dogs may appear, they're still
very much the same genetically, still capable of breeding.

So how can dogs be so different and yet remain genetically so much the
same? Mike Levine thinks the key may lie in stretches of DNA that, until
recently, were dismissed as meaningless.

Only part of the DNA in every cell actually codes for proteins, the
building blocks of life. The rest is a mystery. Some stretches probably are
meaningless. But many geneticists now believe that buried in these mysterious
stretches of DNA are critical instructions for turning genes on and off.

MIKE LEVINE: Turns out that there are two parts to the gene. There's the
famous part, which encodes proteins. Then there's the less-appreciated part,
where I think the real action is, and this is in the so-called "regulatory"
DNA. It tells the protein coding part of the gene where and when to be active.
It is the software of the genome.

NARRATOR: According to Levine, subtle changes in this software
could produce remarkable diversity and do it without changing the DNA that
makes a dog a dog. All these dogs could have the same genes for leg growth, the
only difference may be in when those genes are turned on and off. The
frustration for geneticists like Mike Levine is that, so far, they haven't been
able to crack the code of the regulatory DNA.

MIKE LEVINE: We know the DNA exists, we know that the cis-regulatory DNA
controls in detail where genes are turned on and off, both in development and
in evolution, but we just don't have a handle on the language of that DNA. It's
sort of like discovering the Dead Sea scrolls and not knowing Hebrew. We need
to find a language to decipher the meaning of the cis-regulatory DNA if we're
ever going to understand the functions of complex genomes such as dog genomes
and human genomes.

NARRATOR: Even without being able to read the regulatory DNA,
scientists are convinced of its importance in determining an animal's physical
shape. But what about inherited behaviors, like the unquenchable desire some
dogs have to retrieve? Could they, too, be influenced by when genes are turned
on and off?

It's certainly a part of how biologists explain Charlie's behavior. He has,
to say the least, a very different reaction to sheep than his wolf cousins.
Sheep, to a wolf, are dinner on the hoof. To Charlie, sheep are comrades to
protect from nasty predators like wolves.

It's a bond he formed early in life. When Charlie was a puppy he went
through a stage of life when he was especially open to new experiences. It's
called the "critical period of socialization."

RAY COPPINGER: All animals, all vertebrates, anyway, have this critical
period, where the animal learns what species it belongs to. Birds, they have a
critical period where they learn the species' specific song. If you don't learn
the song, then you can't go out there and sing the song and get a mate. So they
have to learn it. And they can only learn it in this one little window of time.
Now, dogs' critical period for social development is probably about the first
16 weeks.

NARRATOR: At that point, a signal from the genes closes this
critical social window. In wolves, that signal comes when they're about three
weeks old, which means dogs have five times as long to form social
bonds.

RAY COPPINGER: If a dog grows up in its critical period of socialization
in a flock of sheep, then it can socialize with sheep. If it grows up in a
flock of people, it socializes with people. It's very malleable in that kind of
way.

NARRATOR: When genes are turned on and off may also determine
why some breeds are so much better at characteristic activities like herding,
tracking and retrieving. All of these have their roots in the instinctive way a
wolf hunts. Every predator hunts in basically the same way. It starts with
"search," which turns into "eye-stalk" when a potential meal is found. Once
close enough, "chase" begins. "Grab-bite" brings dinner down, and "kill-bite"
finishes the job.

RAY COPPINGER: A wolf, once he starts into the sequence, he's got to go
all the way to the end. So he goes from the searching to the eye-stalk to the
chase, and you can't say, "Look, all right boy, easy, easy, easy—don't go
there," because for the wolf it's appetitive; at the other end of it is a dead
sheep.

NARRATOR: But dogs get their food from people. Even hunting
dogs like this pointer don't need to hunt for a steady meal. That means there's
no downside if the genetic signal for an instinct like stalk or chase is
exaggerated, weakened, or even turned off completely.

RAY COPPINGER: All right,so if I go to the pointer, I have him
searching, he goes into the eye, but I don't care about stalk. I don't want him
to chase, chase is a fault. I don't want him chasing the bird out of there.

If you look at, say, a retriever—I don't care about eye-stalk in a
retriever. I really want the orientation. I want them searching for something,
and when I find it, I want them to go right to grab-bite. So those two stages
in the middle, bango, I don't want those. I just want them to go right to
grab-bite.

Do I want kill-bite? No. And when I get kill-bite in a retriever...that's
called "hard mouth." He stops and eats it, you know? Every retriever man's
worst scenario of all of a sudden the dog stops and eats the bird.

NARRATOR: Tracking, pointing, retrieving, herding, many of the
behaviors we most value in dogs today, are simply aspects of what a wolf does
to survive. Give a dog a job, say, to follow a scent, reward the ones that do
it best, and over thousands of generations a distinct behavior will evolve. The
result is the most diverse mammal on earth. There's more than 400 different dog
breeds and more than 400 million dogs. That's thousands of times more dogs than
wolves. In evolutionary terms, the dog is a real winner.

And some dogs have hit the jackpot, like the lucky few who are regulars at
this Manhattan doggy day care center. Here they can hang with friends, swim in
the pool, enjoy biscuits on demand and the attentions of a personal stylist.
They even take field trips.

GABRIEL (Dog care provider): Sometimes we have...we take the dogs
to Southampton. We're going to have a cruise at the end of November.

NARRATOR: Once primarily working animals, dogs today are
mostly pets. They're frequently chosen more for what they look like than what
they can do or how they behave. But a preoccupation with appearance is not
without consequences. All purebred dogs are products of intensive breeding, and
every year more and more of them suffer from an ever-growing list of genetic
diseases.

Interestingly, the disease problem and the dog's elevated place in our
lives can both be traced to Victorian England. A growing middle class, looking
for ways to show they've arrived, mimic the rich by bringing into their homes
unproductive animals.

HARRIET RITVO (Massachusetts Institute of Technology): So, by the
middle of the 19th century, it was not only ordinary, but highly desirable for
a prosperous, respectable, bourgeois to have a dog or several dogs, and also
several cats.

NARRATOR: These animals are badges of wealth, a declaration
that the owner is rich enough to keep and feed an idle pet. Like lavishly
appointed homes, dogs are status symbols. But as more and more people can
afford them, some way has to be found to anoint a few with the mantle of
aristocracy. So the dog show is born, a competition that's soon restricted to
purebred animals. And since few if any of these dogs herd or hunt, their
quality is judged solely on appearance.

JAMES SERPELL: And that's when you get bizarre and somewhat eccentric
groups of middle class people focusing their lives on breeding perfect animals
in particular breeds.

NARRATOR: In this world, ideas about status, competition, and
the importance of parentage and bloodlines quickly become inextricably
combined.

JAMES SERPELL: The idea of pure blood and breeding pure strains of
things coincided, of course, with a lot of racist talk about refining the
purity of human groups and races. And the breed literature from this early
period, some of it is unashamedly eugenicist and racist.

NARRATOR: And the legacy endures: a preoccupation with
bloodlines and appearance. In the show ring, only purebred dogs are allowed to
compete, and they're judged on how closely they match a written description of
perfection, called the breed "standard."

CHARLOTTE McGOWAN (Papilon Breeder): The standard is the
blueprint for the breed. In this particular breed, the ears are very important:
they're set at a 45-degree angle to the head, just like Allesandro's ears.
They're round, like this, and they're fringed. The skull end is
two-thirds, the muzzle is one-third, the stop is defined, the nose is tapered,
the eyes are round. These are all elements that go into making a perfect
papilon.

NARRATOR: Charlotte McGowan has been showing dogs since she
was eleven.

CHARLOTTE McGOWAN: I'm hoping that I'll still be doing this when I'm 90,
that's why the dogs are getting smaller and smaller.

NARRATOR: Of the ten papilons that live with her, all the
adults have earned the right to be called champion, and the puppies will soon.
What's more, she's convinced she's only begun to tap the greatness in this gene
pool.

CHARLOTTE McGOWAN: We really enjoy the ability to take the gene pool and
use it like paints. It's our art. This is my art. I made this beautiful dog
that I enjoy. I made her—I chose her sire and her dam, I chose several
generations to make this beautiful dog. I'm very proud of her.

NARRATOR: Like most champion show dogs, Bibi is the product of
inbreeding. Her offspring will be too.

CHARLOTTE McGOWAN: Her mother was bred to her mother's grandson to
produce her. And when I choose a mate for her, I'm going to choose her
grandfather who was also her great grandfather. The reason I do the close
breeding is that I have something very good. I want to keep what I have and I
want to improve it. And by closing down the number of potential genes I'm going
to improve my chances of doing that.

NARRATOR: Inbreeding is the only way to finely control what
the next generation will look like, but it comes with a well-documented
downside. Here's why.

Sometimes a gene that helps produce something good, say the shape of a
dog's ears, is located on a dog's DNA close to another gene that produces
something bad, like a disease. When that happens, there's a good chance any pup
getting the good gene will also get the bad one.

Now, as long as the pup gets a healthy version of the gene from the other
parent, he should be all right. But inbred dogs have a much greater chance of
getting the same bad gene from both parents.

So far, Charlotte McGowan has been able to avoid the pitfalls of inbreeding
her papilons. But hundreds of thousands of other purebred dogs are suffering
from genetic diseases.

RAY COPPINGER: The time has come where we've just got to give up this
kind of "master race" mentality that we have about dogs. Our system of breeding
dogs, of isolating small populations called breeds and then practicing
eugenics, generation after generation after generation, all of those dogs are
inbred beyond belief. It's not good genetics and it's not good dog breeding.

NARRATOR: Determined not to give up all they've created, the
dog breeding community has turned to science. If scientists can develop genetic
tests to identify those dogs with bad genes, breeders believe they can do the
rest.

CHARLOTTE McGOWAN: When they find the markers, we can basically select
away from the disease. We can breed, continue to breed beautiful animals, and
we can get rid of the disease.

NARRATOR: If only it were that simple. Only a few bad genes
have been identified, and even then it's uncertain whether enough breeders will
make the sacrifices required to weed them out.

In the meantime, scientists like Karen Overall believe there's a lot these
inbred dogs can teach us about the links between genes and behavior. She's
studying dogs born with a debilitating shyness. Confronted with anything
unfamiliar these dogs freeze. Overall believes they offer a rare window into
the genetic basis of fear and panic.

KAREN OVERALL (University of Pennsylvania): Hello. Look here.
This is one of the affected, what have been called nervous, pointers. Notice
how frozen this dog is. Normally these dogs would come up and do things with
you. I mean, you can...they get so frozen you can actually just move them
around. And he'll stay in this position. This is for...Dogs who are anxious and
withdraw from people are just like a lot of schizophrenic and autistic humans
who withdraw from people and can't interact.

And by understanding the dogs, we have this absolutely marvelous opportunity
to investigate the neurochemistry and the genetics of what goes on in these
people and to suggest treatment.

NARRATOR: Proton scans, a fancy form of MRI, provide Overall
with information on the dog's brain activity and structure. It's her hope
she'll discover levels of certain brain chemicals that correlate with this
intense shyness. In this case, having an inbred extended family is a good
thing.

KAREN OVERALL: With these dogs, we've got brothers and sisters and
mothers and fathers and grandparents and nieces and aunts and cousins, and we
can look at that whole thing, and you can look at the whole disease complex as
a unit. You can look at the behavior, you can look at the neuroanatomy, you can
look at the neurochemistry, you can look at the molecular basis of the
receptors, and you can look at the ultimate genetics. And we can't do that with
people.

NARRATOR: Because the genes of dogs and humans are so similar,
other scientists are using dogs to discover clues to some of the most vexing of
human genetic diseases. With the help of Dobermans like Blitzen and Donner, and
a dachshund named Beau, Emmanuel Mignot has already made a discovery that could
improve millions of human lives. Beau has narcolepsy. At moments of high
emotion, he loses muscle control and appears to fall asleep. Good canned food
is enough to bring on an attack. On the rare occasions when Beau slips off into
the hall, everyone knows there's no reason to race after him.

Narcolepsy is far more common in people than it is in dogs. But it's easier
to study in inbred dogs because they have so much less genetic variation. Not
that it was easy.

EMMANEUL MIGNOT (Stanford University): The process of finding the
gene was a very, very long ordeal. And I have to say, I amazed myself with my
patience. Even so, at the end, you know, we were so tired, and we couldn't
believe we'd finally get the gene.

We discovered something that may have clinical application for narcoleptic
patients, and that is a dream for a researcher. You know, we worked, we looked
hard for this gene, but we would not have dreamed that what we found could have
been useful quickly. And I think there is a good chance that new medication
will come out, directly from that research, for human patients. And that's
really a plus.

NARRATOR: It's another example of how dogs help us.

But how much have we helped them? Sometimes the behaviors we've bred into
dogs aren't well suited to the lives we ask them to lead.

Jennifer and Troy Dow love their Siberian Husky, Emerson, but he's almost
impossible to live with. So they've come to the University of Pennsylvania's
animal behavior clinic. Their hope is that Karen Overall can help them change
his behavior. If she can't, they face the painful prospect of having Emerson
euthanized. Five million dogs a year in the U.S. suffer that fate, most often
because of a behavioral problem.

Most problem dogs, according to Overall, aren't really sick. It's just that
the behaviors bred into them are a poor match for the life they're asked to
lead.

KAREN OVERALL: What most people want in a pet is something that doesn't
shed, that barks a bit but not a lot, that tires easily so that they don't have
to keep up with it, that perhaps maybe even doesn't see or hear so well because
then they're not going to react to lots of things.

Look at a Dalmatian or a vizsla—easy-groom dogs, so everybody thinks,
"great apartment dogs." People don't have any time to groom the dog? Get a
Dalmatian or a vizsla. I've almost never heard of anything so crazy in my life,
because these are dogs that can go 35, 50 miles a day and never get tired.
That's not a great apartment dog.

What we have are breeds that were bred for behaviors that might be
incompatible with being a good pet. Very few of us actually use them to round
up our stock anymore. When herding doesn't have an outlet, or when herding goes
bad, what does it become? It becomes a dog that has to control everything in
its environment, including you.

RAY COPPINGER: You know, if you want a dog to be a good companion, breed
it to be a good companion, breed it to be a good pet. Why do you have to have
your pet have this kind of historic representation of a sled dog, you know?
What does it do for you? It enhances your image as, "I'm a, one of those
rough and tough guys that can go out there and mush my way to the North Pole.
And you know, because I have a Siberian husky, that's kind of
representative of what I would like to be." And so you're using the dog in
order to, you know, project a certain kind of image. No, that's not what you
want. You wanted a good companion, you wanted a pet, you know? The boy and his
dog image, that's what you're looking for, you know? Breed for it. Breed for
it.

JAMES SERPELL: Sometimes I fantasize about somebody in the dog world
coming forward and saying, "Well, let's forget completely about what these dogs
look like, and let's just focus on their behavior. Let's breed the perfect
social companion; let's breed the perfect pet."

I think everybody would win in the long run. Dogs would certainly win because
you would have animals that would be more suitable for living with people in
the modern world, and would be, therefore, less likely to be rejected or
discarded. And people would certainly win because they would have an animal
that gave them the most enjoyment and pleasure.

NARRATOR: It's six months now since Taxi came to live with the
Levines, and most of them have grown to love him.

LILY MIRELS LEVINE: I could imagine leaving my shoes around and not
having them chewed. I can imagine driving my car around and not having it
barfed in. I could imagine a life without a dog, but it's nicer with. And I
think Aaron actually said it the best. 'Cause after we'd had him for a few
weeks—and it was a little, really, rough at the beginning—I was
grumbling, and he said, "But our family is so much jollier with Taxi here." And
it's true.

NARRATOR: Even Mike admits having a dog is sometimes "kind of
nice."

MIKE LEVINE: When he's happy, you know, you see the glow in the eye,
that little tail starts, you know, taking off like a quick propeller, jumps up
on you. And, really, after a long day in the lab, dealing with a lot of
competitive personalities, having this creature greet you in a very
straightforward and honest fashion is really sort of uplifting, I have to say.

NARRATOR: The Levines are determined to do the best they can
by Taxi. Given the long strange journey dogs have made with us, do any of them
deserve less?

Some dogs have not only been our best friends but our most valued helpers,
sniffing for termites, aiding arson investigations, searching for land mines
and more. Find out about dogs and their jobs on NOVA's Web site.

To order this show, or any other NOVA program, for $19.95 plus shipping and
handling, call WGBH Boston Video at 1-800-255-9424.

Next time on NOVA, a high altitude expedition dives into the heart of a
glacier to predict a catastrophe before it strikes. PBS presents NOVA:
Descend Into the Ice.

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